diff --git a/include/utils/Mutex.h b/include/utils/Mutex.h index dd201c898..4fdd27ff1 100644 --- a/include/utils/Mutex.h +++ b/include/utils/Mutex.h @@ -26,6 +26,7 @@ #endif #include +#include // --------------------------------------------------------------------------- namespace android { @@ -45,7 +46,7 @@ public: PRIVATE = 0, SHARED = 1 }; - + Mutex(); Mutex(const char* name); Mutex(int type, const char* name = NULL); @@ -58,6 +59,16 @@ public: // lock if possible; returns 0 on success, error otherwise status_t tryLock(); +#if HAVE_ANDROID_OS + // lock the mutex, but don't wait longer than timeoutMilliseconds. + // Returns 0 on success, TIMED_OUT for failure due to timeout expiration. + // + // OSX doesn't have pthread_mutex_timedlock() or equivalent. To keep + // capabilities consistent across host OSes, this method is only available + // when building Android binaries. + status_t timedLock(nsecs_t timeoutMilliseconds); +#endif + // Manages the mutex automatically. It'll be locked when Autolock is // constructed and released when Autolock goes out of scope. class Autolock { @@ -71,11 +82,11 @@ public: private: friend class Condition; - + // A mutex cannot be copied Mutex(const Mutex&); Mutex& operator = (const Mutex&); - + #if defined(HAVE_PTHREADS) pthread_mutex_t mMutex; #else @@ -117,6 +128,15 @@ inline void Mutex::unlock() { inline status_t Mutex::tryLock() { return -pthread_mutex_trylock(&mMutex); } +#if HAVE_ANDROID_OS +inline status_t Mutex::timedLock(nsecs_t timeoutNs) { + const struct timespec ts = { + /* .tv_sec = */ timeoutNs / 1000000000, + /* .tv_nsec = */ timeoutNs % 1000000000, + }; + return -pthread_mutex_timedlock(&mMutex, &ts); +} +#endif #endif // HAVE_PTHREADS @@ -127,7 +147,7 @@ inline status_t Mutex::tryLock() { * When the function returns, it will go out of scope, and release the * mutex. */ - + typedef Mutex::Autolock AutoMutex; // ---------------------------------------------------------------------------